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Rare star 37 EP

HD 166861

RA 273.5100° · Dec -34.2892° · star

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Score breakdown

· 7 badges
37 pts · Rare
Rare 50 pts → Epic
  • Toward the galactic centre +8
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Giant star +6
  • Blue-white star +5
  • Star +3
  • On the zodiac +3
Total score 37

13 more points to reach Epic.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Toward the galactic centre · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Giant star · +6
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B8/B9III — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 7.9 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Sagittarius.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around June — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

  • Aboard Voyager 1. ≈ 25.7 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 2.3 million years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
-0.348
bv
-0.016
constellation
Sgr
dist ly
1462.583
luminosity
120.0052
mag
7.91
name
HD 166861
spect
B8/B9III

About HD 166861

HD 166861 is a rare star. It lies about 1,462.6 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 7.91 and has spectral type B8/B9III.

Its spectrum reads B8/B9III — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for HD 166861 in the constellation Sgr. At apparent magnitude 7.91, it is an easy target for binoculars.

Like any astronomical target, HD 166861 is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why HD 166861 is a rare star

HD 166861 scores 37 points on Spacedle's rarity scale, which places it in the rare tier. Another 13 points would lift it into a rarer tier.

That score comes from 7 science badges — Star, Distant (over 1,000 light-years), Toward the galactic centre, On the zodiac, Hot blue B-type star, Giant star and Blue-white star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.